engine stalling

[1jack99]

Im new here so this has prob. been asked, Thanks in advance.

I own a 1996 GMC 1500 TD. it is approaching 300 K and has been a GREAT truck. I have replaced the fuel filter a couple of times in the last couple of years. The problem is I get down the road fine. Its when I get to an Idle it dies every now and then. I has done it for many years but always starts right back up. It used to do this ever 6 months or so and only one time when it did it. Now sometimes I cant get across and inter section with it. Like I said it stalls and will start back up, idle for a few sec. and die again. I have only had one time it would not restart. I left it in the church parking lot for two days scratching my head and went to get it towed home and it started right up and drove home fine. I have been in the automotive field all my life and I am very good at any gas car or truck. But I am stupid when it comes to this truck but I love it and don't want to sell it. I could just replace the motor with a gas engine but the damn things runs like brand new outside of this issue... any ides would be greatly appreciated.

[a5150nut]

Get a can of spray electrical contact cleaner and clean all conections on motor. Clean all ground connections, right rear corner on head, batteries. ect.

Any codes set?

Start there and see if that helps. Cheap things first.

[racer55]

PMD is failing or ignition switch burning out.
Does the dash die at the same time but radio and blower motor keep working?

Also check lift pump operation,with the engine idling(safely in park) open the water in fuel drain Tee-valve located near the thermostat housing and note if the engine stalls or keeps running.
If it stalls quickly-diagnose why the LP isn't pumping adequate fuel.

[JohnC]

Probably more than you ever wanted to know about stalling here. (http://www.thedieselpageforums.com/tdpforum/showthread.php?t=2938)

[1jack99]

Hello All that replied I am sorry for the late post as I have been so busy with my Limo Company. So answers in order

5150 your my kind of person as I hate spending money lol especially in these times. I will clean all connections as that makes sense to me. I have owned this truck for close to 9 years bought it for 4K and I swear that it is the best thing I have ever owned. I have had to replace the batteries twice in that time but out side of oil changes and fuel filters I have not done a thing to it mechanically. I only wish I could say that on my other cars ha!

Racer55 This is a stupid question I have seen this PMD statement a lot what the hell is it, and where is it please. I have done the thing with the lift pump but that was a few years ago. I do believe the radio keeps playing but I have no idea about the blower motor. I does feel like you turn the ignition switch of when it happens, does not feel like it is running out of fuel.

[rapidoxidationman]

The PMD (Pump Mounted Driver, also known as the FSD - Fuel Solenoid Driver) is an electronics black box mounted on the injection pump in the engine valley between the cylinder heads. It's a high heat area and the PMD is mounted on the driver's side of the IP (injection pump) beneath the intake manifold so the flow of fuel through the pump can keep the PMD cool. The PMD generates a lot of heat itself by turning on and off the large (read: high current) transistors inside it to do the job of controlling the injector pump - hence the need for cooling.

The heat seems to be what kills these boxes, and the aftermarket has come up with a better heat removal solution than the GM engineers: Mounting the PMD on a large heat sink and mounting it on the side of the engine bay using an extension cable to keep it connected electrically to the IP. Kennedy (a member and vendor on this site) makes a pretty slick package including the PMD, cable, and heat sink. I installed it on my '96 when I cooked my second PMD around 225,000 miles. The heat sink just plain works: The PMD barely got even warm to the touch after relocating it.

If you've gone 300K without replacing the PMD, you're lucky - and you're due...